The food and nutrition manufacturing sector is one of the most energy-intensive segments of the process industry. It encompasses everything from beverage and dairy production to baking, oilseed processing, nutritional supplements, and infant food manufacturing. Energy is consumed across a wide range of operations (such as heating, cooling, drying, mixing, sterilising, packaging, and other) often with complex temperature and hygiene requirements.
Improving energy efficiency in this sector not only reduces operating costs and greenhouse gas emissions but may also enhance product quality, reliability, and competitiveness.
Energy Consumption Breakdown
Energy demand in the food industry typically consists of a mix of thermal energy (steam, hot water, and direct heat) and electrical energy (motors, refrigeration, air handling, and compressed air). The breakdown varies depending on the product type and process configuration, but typical patterns include:
Thermal processes (40–60%): Pasteurisation, sterilisation, evaporation, cooking, drying, and spray drying all require substantial heat, commonly provided by steam or natural gas-fired systems.
Refrigeration and cooling (15–25%): Cold storage, chilling, and freeze-drying consume large amounts of electricity, especially in dairy, meat, and frozen product lines.
Mechanical and electrical systems (10–20%): Mixing, conveying, and packaging equipment draw significant motor power.
Compressed air and utilities (5–10%): Compressed air is widely used for control systems and packaging operations, while lighting and HVAC contribute a smaller but continuous load.
Overall, energy costs can represent 15–30% of total production costs in food processing plants, making efficiency improvements a key competitiveness factor.
Opportunities and Challenges for Improving Energy Efficiency
Energy efficiency in the food sector is often constrained by factors such as hygiene standards, batch variability, and the need for precise temperature control. Processes like pasteurisation or spray drying require consistent heat input to ensure food safety and quality, which can limit flexibility. However, because many operations involve repeated heating and cooling cycles, there are major opportunities for heat recovery and process integration.
Other challenges include fluctuating production schedules, product mix changes, and high cleaning-in-place (CIP) energy use. Addressing these requires both technological upgrades and smarter operational management.
Technology Assessment of Energy Efficiency Measures
Heat Recovery and Process Integration
Food manufacturing processes frequently discharge warm effluent, condensate, or exhaust air that still contains usable heat. Heat exchangers and thermal recovery systems can capture this energy to preheat process water, CIP solutions, or incoming air for dryers and ovens.
In dairy or infant formula production, whey evaporators and spray dryers can recover waste heat to preheat feed streams or regenerate dryer air. In baking, oven exhaust recovery units can reclaim up to 30% of thermal energy. Applying pinch analysis across the process identifies optimal points for heat exchange and integration, enabling up to 20% overall fuel savings.
Steam and Boiler System Optimisation
Boilers are central to most food plants, supplying steam for cooking, sterilisation, and cleaning. Efficiency can be improved through economisers, condensate recovery, and automated oxygen control for combustion optimisation. Reducing boiler pressure, insulating steam lines, and maintaining steam traps also yield quick savings.
A well-maintained condensate return system can recover 70–90% of condensate, reducing both fuel and water treatment costs. Many facilities achieve 5–15% reductions in fuel consumption through systematic steam audits and maintenance programs.
Electrification, Hybrid Electric-Gas Systems and Biomass Boilers
Low- to medium-temperature processes such as pasteurisation, drying, or preheating can increasingly be electrified using heat pumps, electric boilers, and infrared or microwave heating. These systems can operate with renewable electricity, offering near-zero carbon heat. High-temperature processes, such as baking or roasting, can also benefit from hybrid electric-gas systems or biomass boilers. While capital costs may be higher, electrification reduces carbon intensity and can provide flexible operation aligned with renewable energy availability.
High Efficiency Refrigeration Systems
Refrigeration is one of the largest electrical loads in food manufacturing. Improvements include variable-speed compressors, high-efficiency evaporators and condensers, and ammonia or CO₂ systems that outperform traditional HFC refrigerants. Heat rejected from refrigeration systems can also be recovered for process heating or domestic hot water, improving overall plant energy balance. Good system design, regular defrost scheduling, and maintaining correct refrigerant charge are essential for optimal performance.
Compressed Air System Optimisation
Compressed air is vital for automation, packaging, and instrumentation but is often poorly managed. Regular leak detection, pressure optimisation, and installation of variable speed drives (VSDs) on compressors can yield savings of 20–30%. Reducing system pressure by just 1 bar can cut energy use by about 7%. Heat recovery from compressor cooling can also supply hot water for cleaning or preheating.
Energy Efficient Drying, Evaporation, and Concentration
Drying and evaporation are some of the most energy-intensive operations in food and nutrition production, particularly in milk powder and infant formula plants. Upgrading to multi-effect evaporators, mechanical vapour recompression (MVR), and spray dryers with heat recovery can cut steam consumption by up to 50%.
Fluidised-bed dryers, high-efficiency nozzles, and improved airflow management further enhance performance. Proper maintenance and process control are critical to prevent fouling and maintain consistent efficiency.
Advanced Process Control, Real-Time Monitoring, and Energy Management Systems
Digitalisation is transforming energy management in food manufacturing. Advanced process control (APC), real-time monitoring, and energy management systems (EnMS) allow plants to optimise heating, cooling, and equipment operation based on demand. Installing sub-metering for major energy users (boilers, chillers, compressors, and dryers) helps identify inefficiencies quickly. Machine learning and predictive analytics can fine-tune processes, reduce idle time, and prevent overprocessing, leading to 5–10% energy savings.
Energy Efficient Cleaning-in-Place (CIP) and Water Heating
CIP systems often run multiple times per day, consuming large quantities of hot water and chemicals. Optimising CIP cycles through heat recovery from wastewater, insulation of tanks and lines, and automatic control of rinse volumes can reduce energy and water use by 20–30%. Reusing final rinse water for pre-rinsing, maintaining heat exchangers, and monitoring cleaning solution temperatures are simple, high-return measures.
Energy Efficient Building Services
HVAC, lighting, and ventilation systems also contribute significantly to energy consumption, especially in cleanrooms or temperature-controlled production areas. Upgrading to LED lighting, high-efficiency fans, and smart ventilation systems reduces electrical load while maintaining hygiene and comfort standards. Integrating heat recovery into air-handling systems further enhances efficiency.
ISO 50001 Energy Management System
Energy efficiency in food and nutrition manufacturing is not only a matter of technology but also of behaviour and management. Implementing a formal energy management system (ISO 50001) ensures systematic monitoring, target setting, and continuous improvement. Training operators to recognise energy-intensive practices, such as unnecessary equipment idling or excessive cooling, reinforces long-term performance.
Production scheduling can also influence efficiency: grouping similar product runs reduces the number of CIP cycles and temperature transitions, lowering both heat and water demand. Periodic benchmarking against best-in-class facilities helps track progress and identify new opportunities.
Sustainability and Decarbonisation Strategies
Energy efficiency measures complement broader sustainability strategies in the food sector, such as waste heat utilisation, renewable energy integration, and carbon-neutral production goals. Many food manufacturers are now combining efficiency upgrades with on-site solar or biogas systems, waste-to-energy recovery, and green procurement initiatives. For example, recovering biogas from wastewater treatment can offset part of the thermal demand for boilers, while solar photovoltaic systems can supply low-voltage electrical loads during daytime production.